Floatable rocket launcher



18, 1966 J. W.SEMONIAN ETAL 3,

FLOATABLE ROCKET LAUNCHER Filed June 19, 1964 INVENTORS JOSEPH W.SEMONIAN ATTORNEY United States Patent 3,279,319 FLOATABLE ROCKETLAUNCHER Joseph W. Semonian, Camarillo, and Gary T. Purse],

Oxnard, Calif., assignors to the United States of America as representedby the Secretary of the Navy Filed June 19, 1964, Ser. No. 376,599 4Claims. (Cl. 891.810)

The invention described herein may be manufactured and used by or forthe Government of the United States of America for governmental purposeswithout the payment of any royalties thereon or therefor.

The present invention relates in general to floatable rocket launchersand more particularly to a floatable closed breech rocket launcher whichis effective in launching rockets from launching tubes without recoil ofthe launch tubes.

Since the change in emphasis from land based launching of rockets andmissiles, occasioned by excessive costs and dangers to personnel amongother considerations, to launchings from water various devices andmethods have been suggested for improving techniques in the launching ofthe missiles or rockets from bodies of water. Some of the prior attemptsat improving water-launching of missiles or rockets have been centeredprimarily upon attaching floats to the upper end of the rocket, thesefloats to be rejected or forced aside upon the rocket engine beingignited and the missile moving upward out of the water. Launchingrockets from bodies of water through the use of launching tubes havingclosed lower ends would be particularly undesirable because of therecoil or down- Ward thrust upon firing of the rocket engine whichdownward thrust would result in a reduction in stroke of the rocket inrelation to the water surface which could otherwise be utilized, and ameans for introducing inaccuracies in the launch of the vehicle sincethe downward thrust may be exaggerated or amplified by wave action inthe launch area.

The present invention avoids the disadvantages of prior launching tubesand provides an additional velocity of the rocket at exit from thelaunching tube which in a closed-end launching tube would be reduced bythe recoil of the launching tube.

The invention also avoids the energy losses entailed in the use oflaunching tubes having open lower ends through which exhaust gases comedirectly in contact with the body of water. These gases are diffused andalso churn the water into a mixture of drops of cold water in gas whichsignificantly reduces the heat of the gases and therefore the additionalacceleration of the rocket.

The present invention thus basically is a device and method for use witha launching tube wherein substantially the full exhaust force of the hotexhaust gases is utilized to impart additional acceleration to arocketpropelled vehicle during the launching stage of its flight.

Accordingly, it is an object of the present invention to provide meansto be used in combination with a launching tube for imparting additionalacceleration to a rocket propelled vehicle without the introduction ofadditional forces.

It is another object of the present invention to provide a rocketlaunching tube for water launching in which no additional buoyancyapparatus or member is required to float the combined launching tube androcket.

It is a further object of the present invention to provide asubstantially recoilless device and method for launching rockets whereinthe gases supplied by the exhaust products of the rocket are utilized inimparting additional acceleratiton to the rocket.

It is a still further object of this invention to provide in combinationwith a water-launch tube a device and method which utilize the force ofthe exhaust products of the rocket engine throughout the travel of therocket in the launcing tube.

Other objects and many of the attendant advantages of this inventionwill be readily appreciated as the same becomes better understood byreference to the following detailed description when considered inconnection with the accompanying drawings in which like referencenumerals represent like parts throughout and wherein:

FIG. 1 is a longitudinal cutaway view party in section of one embodimentof the invention;

FIG. 2 is a schematic View of the embodiment of FIG. 1 shortly after therocket engine has been ignited; and

FIG. 3 is a schematic view of the embodiment of FIG. 1 showing thecomponents after the rocket has left the launching tube.

Referring now to FIG. 1, a rocket or missile 11 is shown centrallysupported within a launching tube 12 which floats at water level 13.Spacer :means 17 are disposed at the forward and aft ends of the missileand, for increased clarity, only two of the four spacer means are shown.Missile 11 in the pre-launch stage rests on a piston assembly 18, themissile and piston assembly being disposed in the upper portion oflaunching tube 12 and held in place vertically therein my removablemeans" such as a set screw 20. Launching tube 12 is closed at its upperend 21 by a frangible diaphragm 22 and gasket 23 and is open at itslower end 24. About the lower end 24 is disposed ballast 29 in the formof a removable ring.

Piston assembly 18 in the present embodiment is in the form of a pair ofopen-ended pistons assembled together in a watertight fit with the openend of the upper piston 31 extending outward of and enclosing the openend of the lower piston 32. Before ignition of the rocket engine ofmissile 11, the upper and lower pistons, 31 and 32, are held together byshearable means such as shear pins 34 which are inserted before thepiston assembly is placed within launching tube 12 at points which inthe pre-launch stage are above an opening 37 in the launching tube wallfor accommodating set screw 20. Thus the weight of missile 11 istransmitted to upper piston 31 and. thence to set screw 20 therebypreventing the missile and piston assembly from sliding downward in thelaunching tube. Since in this embodiment the open lower end 24 permitsfree entry of water at ambient pressure, the piston assembly 18 isprecluded from moving upward under pressure of the water by a stop meanssuch as a. relatively small ring 36 of metal welded to the wall of lowerpiston 32. Lower piston 32 is also restrained from movement upwardwithin upper piston 31 by stops 38.

The piston assembly 18 is made to fit snugly within launcher tube 12 butnot in watertight relationship therewith for reasons to be discussedlater. A significant space is provided between the outer bearing surface40 of the upper piston 31 and the outer bearing surface 41 of lowerpiston 32 to permit some flow of water between these bearing surfacesand the inner surface of launching tube 12. However, lower piston 32 iscontained within upper piston 31 in watertight relationship. The nozzle43 of missile 11 is sealed in watertight fit by frangible diaphragm 45and gasket 23. Rocket 11 and upper piston 31 are held in detachableengagement by forwardly extending straps or bars 50, the straps beingcurved to conform to the outer configuration of the missile and held inplace against the missile by the removable spacers 17. At their lowerend opposite the nozzle 43 opening the straps 50 are turned outward andheld in place under clamps 52 by the weight of the missile. Clamps. 52must have suflicient strength to hold the piston. assembly 18 andmissile 11 together under the forces exerted by exhaust gases emanatingfrom the missile 11. The

clamps 52 and straps 50 must also have a strength in excess of that ofshear pins 34. A plurality of openings such as 54 are provided aselected distance below closed upper end 21 to permit the entrance ofwater therein.

' FIGS. 2 and 3 show different stages in operation of the device andwill be described in conjunction with a partial description of operationfeaturing the recoilless or substantially recoilless action of thelunching tube of the present invention. Preliminarily, FIG. 2 shows theposition of upper piston 31 and lower piston 32 at a very short timeafter the rocket has been fired. Spacers 17 are still in position beingheld thus by the presence of the lower spacer within the launching tube12. Forwardly extending straps 50 are still held in an upright position.The force of exhaust gases against upper piston 31 serves to retain thatpiston in contact with the after end of the missile 11. Lower piston 32has moved downward a lesser distance than upper piston 31 has movedupward because of the greater resistive force against lower piston 32,namely, the ambient water pressure. In FIG. 3, the

internal launching tube pressure created by the exhaust gases has forcedboth upper piston 31 and lower piston 32 out of the launching tube 12,and spacers 17 as well as straps 50 have fallen off to the side ofmissile 11. Upper piston 31, no longer having exerted against it theconfined exhaust gases, has dropped away from the missile 11.

The operation of the device will now be supplemented beginning with theassembling of the missile, upper piston and lower piston in thelaunching tube. This assembly may be effected on board ship or at someconvenient site, and after such assembly the combined components arelowered into the Water at the position selected for launching missile11. Frangible diaphragm 22 must be secured in place before support iswithdrawn from the assembled components. This diaphragm and diaphragm 45may be made of styrefoam or polyurethane. Frangible diaphragm 45 is, ofcourse, installed before the upper and lower pistons are connectedtogether and held together by shear pins 34. Set screw is inserted afterthe piston assembly 18 has been properly positioned in the launchingtube 12. Upon the piston assembly 18 being positioned opposite set screw20, such that the set screw 20 will enter into the space bounded by thelower end of the downwardly depending walls of the upper piston 31, thering 36 and the upwardly extending walls of lower piston 32, the setscrew is inserted to hold the assembled missile and pistons within thelaunching tube at the desired position therein. The combined componentsare then lowered into the water, piston downward, and the launching tube12 is allowed to partially fill by water entering the bottom opening 24and flowing past the piston assembly 18 upward to the space between thespacers -17 and upward beyond the openings 54. The air entrapped in theupper portion of the launching tube 12 provides buoyancy for allcomponents of the device, the level of the water in this space beingdetermined by the position and size of openings 54. At this stage, theentire assembly is ready for ignition of the rocket engine. Any firingcords will have been connected so that upon the area being cleared forfiring the rocket engine may be ignited as desired.

Upon firing of the rocket engine, exhaust gases are discharged into thehollow piston assembly, the clamps 52 and forwardly extending straps 50having suflicient strength to retain the missile 11 and upper piston 31connected during the initial shock of discharge of exhaust gases. Theforce of the exhaust gases entering the space enclosed by the upper andlower pistons will sever shear pins 34 thereby permitting the upperpiston 31 to rise with the rocket 11 and having lower piston 32 drivenin the opposite direction. The lower piston must drive the waterentrapped below it out of the lower portion of the launching tube. Themotion of the lower piston allows the tube to remain motionless. As moregases emanate from the rocket engine, the forces they create causefurther separation of the upper and lower pistons with the upper pistondriving the missile out of the launching tube with an additionalacceleration to that imparted to the missile 11 by the acceleration ofthe exhaust gases alone. In this manner, the entire enclosure within thelaunching tube between the pistons is used as an expanding chamber orvolume. The exhaust gases are thus confined in this enclosed space andtheir full force is made effective in assisting the launch of themissile 11. As missile 11 emerges from the launching tube, spacers 17will fall away from the body due to their weight and air flow along thesurface of the missile. As the lower portions of the spacers 17 clearthe launching tube, the spacers fall away completely from the missile11. As upper piston 31 clears the launching tube, forwardly extendingstraps 50 will fall downward because of their weight and free the pistonfrom the missile thereby permitting the missile to proceed in itsprogrammed attitude.

It will thus be appreciated that the device of the present invention andthe method entailed in accelerating a missile from a launching tubeprovide full use of exhaust gases and avoid objectionable recoil of thelaunching tube at launch. The present invention is an adaptation of theconcept of the recoilless gun for use as a floating missile launcher. Bysuitable selection of the dimensions of the launching tube aft of themissile, and by the characteristics of the water exit or bottom tubeopening 24, it is possible to provide a launch system where the :forceson the launcher are balanced and recoil is substantially eliminated orcontrolled. The present launcher also avoids the necessity of a breechvoid large enough to prevent excessive breech pressure after ignition ofthe rocket engine. Such a void would require ballast to immerse thedevice to a desired depth, and thus penalties of both weight and sizeare avoided in the present invention. The present invention in factavoids any requirement for separate ballast means by flooding only aportion of the launching tube and using the confined unflooded portionfor necessary ballast.

It will be appreciated that the present launcher will also operatewithout the piston assembly installed therein. In a device using thepiston assembly as taught herein, the expansion of exhaust gases is ormay be assumed to be adiabatic whereas such would not exist in the casewhere no lower piston is used. The present invention thus provides asimple yet eflicient method for increasing the initial acceleration of amissile launched from a verti cal floating position.

It will be recognized that many modifications and variations of thepresent invention are possible in the light of the above teachings. Itis therefore to be understood that within the scope of the appendedclaims the invention may be practiced otherwise than as specificallydescribed.

, We claim:

1. A device for eliminating launch tube recoil in a fioatable rocketlauncher using a launching tube comprising:

a launching tube sealed at its upper end by a frangible diaphragm andopen at its lower end;

a piston assembly detachably supported in the lower portion of saidlaunching tube;

a rocket in said launching tube supported by and detachably connected tosaid piston assembly;

spacing means maintaining said rocket centrally disposed in saidlaunching tube; and

means intermediate the ends of the launching tube for admitting waterinto said launching tube to a level suflicient to float the launchingtube, rocket and piston assembly in an upright attitude;

' said piston assembly separating and confining rocket exhaust gases inthe launching tube upon firing of said rocket;

so that the gases emanating from said rocket will propel portions ofsaid piston assembly in opposite directions within the launching tubethereby avoiding unbalanced thrusts on the launching tube.

2. The device as defined in claim 1 wherein said piston assemblyincludes an upper piston detachably supported in said launching tube anda lower piston detachably connected to said upper piston; and

frangible diaphragm means sealing the nozzle of said rocket;

said piston assembly mounted in non-watertight fit within said launchingtube;

said upper piston and said lower piston detachably connected inwatertight fit;

so that upon firing of the rocket exhaust gases will burst saidfrangible diaphragm means and enter said piston assembly separating saidupper and lower pistons and detaching said upper piston from thelaunching tube.

3. The device as defined in claim 2 wherein said upper piston and saidlower piston are hollow in form having open adjacent bases, said upperpiston having side walls depending downward and said lower piston havingside walls extending upward in said launching tube.

4. A device for eliminating launch tube recoil in a floatable rocketlauncher using a launching tube comprising:

a launching tube sealed at its upper end by a frangible diaphragm;

a piston assembly detachably supported in the lower portion of saidlaunching tube;

a rocket in said launching tube disposed upon and detachably connectedto said piston assembly; spacing means maintaining said rocket centrallydisposed in said launching tube;

means admitting water into said launching tube to a level sufiicient tofloat said launching tube in an upright attitude;

said piston assembly separating upon firing of said rocket;

said piston assembly including an upper piston detachably supported insaid launching tube and a lower piston detachably connected to saidupper piston;

frangible diaphragm means sealing the nozzle of said rocket;

said piston assembly mounted in non-watertight fit within said launchingtube;

said upper piston and said lower piston. detachably connected inwatertight fit;

said upper piston and said lower piston hollow in form and having openbases;

said upper piston having side walls depending downward and said lowerpiston having side walls extending upward in said launching tube; and

said means admitting water into said launching tube including aplurality of orifices positioned a selected distance below the uppperend of said launching tube such that a sufficient space is providedabove said orifices to entrap the volume of air necessary to float saidlaunching tube at a desired depth;

so that the gases emanating from said rocket will propel said pistonassembly in opposite directions within the launching tube therebyavoiding unbalanced thrusts on the launching tube, and upon firing ofthe rocket exhaust gases will burst said frangible diaphragm means andenter said piston assembly separating said upper and lower pistons anddetaching said upper piston from the launching tube.

References Cited by the Examiner UNITED STATES PATENTS 3,084,600 4/1963Walker s9 1.7

3,128,670 4/1964 Blacker s9 1.7 3,135,161 6/1964 Oyhus s9 1.7

3,137,203 6/1964 Brown s9 1.7

FOREIGN PATENTS 29,662 12/1884 Germany. 125,652 5/1919 GreatBritain.

BENJAMIN A. BORCHELT, Primary Examiner.

SAMUEL W. ENGLE, Examiner.

1. A DEVICE FOR ELIMINATING LAUNCH TUBE RECOIL IN A FLOATABLE ROCKETLAUNCHER USING A LAUNCHING TUBE COMPRISING: A LAUNCHING TUBE SEALED ATITS UPPER END BY A FRANGIBLE DIAPHRAGM AND OPEN AT ITS LOWER END; APISTON ASSEMBLY DETACHABLY SUPPORTED IN THE LOWER PORTION OF SAIDLAUNCHING TUBE; A ROCKET IN SAID LAUNCHING TUBE SUPPORTED BY ANDDETACHABLY CONNECTED TO SAID PISTON ASSEMBLY; SPACING MEANS MAINTAININGSAID ROCKET CENTRALLY DISPOSED IN SAID LAUNCHING TUBE; AND MEANSINTERMEDIATE THE ENDS OF THE LAUNCHING TUBE FOR ADMITTING WATER INTOSAID LAUNCHING TUBE TO A LEVEL SUFFICIENT TO FLOAT THE LAUNCHING TUBE,ROCKET AND PISTON ASSEMBLY IN AN UPRIGHT ATTITUDE; SAID PISTON ASSEMBLYSEPARATING AND CONFINING ROCKET EXHAUST GASES IN THE LAUNCHING TUBE UPONFIRING OF SAID ROCKET; SO THAT THE GASES EMANATING FROM SAID ROCKET WILLPROPEL PORTIONS OF SAID PISTON ASSEMBLY IN OPPOSITE DI-